In the conventional fabrication of microelectronic integrated circuits (I.C.'s), a variety of dielectric films (e.g., SiO2, Si3N4), semiconductor films (e.g., epitaxial Si, polycrystalline Si, GaAs) and conductor films (e.g., W, WSi2, TiN) are deposited by chemical vapor deposition (CVD) processes. These CVD processes are well known in the semiconductor processing field and can be classified into the following categories: